Pseudovirions as Specific Tools for Investigation of Virus Interactions With Cells

This chapter outlines the generation and application of human papillomavirus type 33 (HPV33) pseudovirions. The method describes (1 ) the construction of vaccinia viruses recombinant for the major and minor HPV capsid proteins, L1 and L2, respectively; (2 ) the transfection of Cos7 cells with a marker plasmid replicating to high copy numbers; (3 ) the expression of L1 and L2 using the vaccinia virus expression system; (4 ) the extraction, purification, and analysis of HPV33 pseudovirions; and (5 ) their use in pseudoinfection assays. These pseudovirions are structurally indistinguishable from native virions and are therefore valuable tools for the study of papillomavirus-cell interactions. The methods described can be adopted for other nonenveloped DNA viruses and may be useful for gene transfer.